Twin wheel castor



FIG. 1 is a front elevational view of a twin wheel castor showing my new design;

FIG. 2 is a left side elevational view thereof;

FIGS. 3 and 4 are respectively top and bottom plan views thereof;

FIG. 5 is a right side top and rear perspective view thereof; and

FIG. 6 is a rear elevational view thereof. 

The ornamental design for a twin wheel castor, as shown and described. 